Role in pathogenesis and parasite cell biology of the trans-sialidase from Trypan

锥虫转唾液酸酶在发病机制和寄生虫细胞生物学中的作用

• 批准号: 9252364
• 负责人: Oscar Eduardo Campetella
• 金额: $ 13.42万
• 依托单位: INSTITUTE/RESEARCH/BIOTECHNOLOGY FDN
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9252364
• 关键词: 5' Untranslated Regions; Alpha Cell; Antigen-Presenting Cells; Antigens; Area; Argentina; Australia; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; Biological; Biological Assay; Biology; Blood Circulation; Cell Cycle; Cell surface; Cells; Cellular biology; Chagas Disease; Chemicals; Chronic; Country; Cytolysis; Developed Countries; Developing Countries; Economics; Electron Microscopy; Enzymes; Event; Galactose Binding Lectin; Galectin 3; Gene Expression; Genes; Glycobiology; Glycoconjugates; Goals; Graft Rejection; Health; Immune; Immune response; Immune system; Infection; Inflammation; Inflammatory Response; Japan; Kinetics; Knockout Mice; Knowledge; Latin America; Learning; Lectin; Leukocytes; Life Cycle Stages; Link; Lymphocyte; Mammals; Mastigophora; Mediating; Metabolic Pathway; Modeling; Molecular; Mucins; Mus; PTPRC gene; Parasites; Parasitic Diseases; Pathogenesis; Pathology; Pathway interactions; Patients; Pattern; Phenotype; Physiological; Physiology; Process; Production; Protein Isoforms; Proteins; Public Health; Recombinants; Reporter; Risk; Role; Serum; Sialic Acids; Signal Transduction; Site; South America; Spain; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Surface; T-Cell Receptor; T-Lymphocyte; Testing; Th1 Cells; Therapeutic; Transgenic Mice; Transplantation; Trypanosoma cruzi; Vacuole; Variant; Virulence; Virulence Factors; chemotherapy; fight against; glycosylation; immunoregulation; migration; mouse model; neglected tropical diseases; neutralizing monoclonal antibodies; pathogen; public health relevance; response; sialylation; social; sugar; tool; trafficking; trans-sialidase; vector

DESCRIPTION (provided by applicant): Chagas disease, the American trypanosomiasis, is a chronic disabling parasitic disease caused by the flagellate protozoon Trypanosoma cruzi. It is considered a neglected tropical disease. With an estimated total of 100 million people at risk, about 8-10 million already infected, and about 40,000 new cases/year, Chagas disease represents a major health, social and economic problem in Latin America. The infection is naturally transmitted by triatomine vectors ("kissing bugs"), from the southern USA to the south of South America. However, chagasic patients are in fact dispersed worldwide due to migration from the endemic region to economically-developed countries. Therefore, Chagas disease is emerging in many non-endemic countries (Australia, Japan, Spain, etc). Infected people in Argentina are estimated at about 1,600,000 and in the USA at about 300,000-1,000,000. Although crucial in its life cycle, T. cruzi is unable to synthesize sialic acids. The parasite scavenges it from the mammalian host glycoconjugates through an enzyme known as trans-sialidase. This enzyme is a shed virulence factor that induces alterations in the host immune system, favoring the parasite colonization process. Our long-term aim is to fully clarify the relevance of this virulence factor to parasite biology, life cycle virulence and pathogenesis, and to understand the alterations induced on the immune system physiology. Understanding the manipulation of the immune response by pathogens allows a better fight against the infection and also helps to learn more about the immune system physiology, and eventually to transfer this knowledge to the therapeutic handling of other pathologies (autoimmune diseases, transplant rejection, inflammatory responses, etc.). This project proposes to disclose the relevance -to pathogenesis and parasite biology, at cellular and molecular levels- of the acquisition process of the sialyl residue performed by the trans-sialidase acceptor molecules on the parasite and lymphocyte surfaces. To achieve these goals we will a) use genetically-modified parasites transfected with modified transporters to accurately determine TS intracellular trafficking; b) follow the unnatural sugars approach as bioorthogonal chemical reporters to clearly identify acceptor molecules and their fate and function on parasite and white cell surfaces; c) search for the induced alterations of known immune responses using T-cell receptor transgenic and KO mice models; and d) test genetically-modified parasites to analyze the association of TS inactive isoforms with virulence factors and pathogenesis.

描述(申请人提供)：恰加斯病，美国锥虫病，是一种由鞭毛虫原虫克氏锥虫引起的慢性致残性寄生虫病。它被认为是一种被忽视的热带疾病。据估计，恰加斯病总共有1亿人面临风险，约有800万至1000万人已经感染，每年约有4万新病例，恰加斯病是拉丁美洲的一个主要健康、社会和经济问题。这种感染是通过三聚氰胺媒介(“接吻的虫子”)从美国南部传播到南美洲南部的。然而，由于从流行地区向经济发达国家的移徙，查格斯病患者实际上分散在世界各地。因此，恰加斯病正在许多非流行国家(澳大利亚、日本、西班牙等)出现。据估计，阿根廷的感染者约为160万人，美国约为30万至100万人。尽管在其生命周期中至关重要，但克氏锥虫不能合成唾液酸。这种寄生虫通过一种名为反式唾液酸酶的酶从哺乳动物宿主糖共轭中清除它。这种酶是一种脱落的毒力因子，可以引起宿主免疫系统的变化，有利于寄生虫的定植过程。我们的长期目标是充分阐明该毒力因子与寄生虫生物学、生命周期毒力和致病机制的相关性，并了解其对免疫系统生理的影响。了解病原体对免疫反应的操纵可以更好地对抗感染，还有助于了解更多关于免疫系统生理学的知识，并最终将这些知识转移到其他病理(自身免疫性疾病、移植排斥反应、炎症反应等)的治疗处理中。该项目建议在细胞和分子水平上揭示反式唾液酸酶受体分子在寄生虫和淋巴细胞表面执行的唾液酸残基获取过程与致病机理和寄生虫生物学的相关性。为了实现这些目标，我们将a)使用转运蛋白修饰的转基因寄生虫来准确地确定TS的细胞内转运；b)按照非天然糖的方法作为生物正交化学记者来清楚地识别受体分子及其在寄生虫和白细胞表面的命运和功能；c)利用T细胞受体转基因和KO小鼠模型来搜索已知的免疫反应的诱导改变；以及d)测试转基因寄生虫以分析TS非活性亚型与毒力因子和致病机制的关联。